I was fairly sure there's an issue for this (it also linked this to restarting game), but can't find one right now. Basically, the problem is that after a while input items pile up in machines that are set for autocrafting. This can be worked around to some degree by using crafting cleanup upgrades everywhere, but it probably will break with more complex machines and isn't great either way.

In fact，I find the carft pipe don't save the carfting info when closing the game. If the carft pipe is make something, you can using pipe_controller to see the number , type and destination. Then restrat the game the info about number , type and destination will disappear.

It's not "as intended". In case I'm talking about recipe fully describes all outputs and items are properly extracted most of the time, yet few manage to get stuck for whatever reason. Crafting cleanup is just a workaround.

Yes, you need to use crafting cleanup upgrades as intended.

Well, under some conditions machines get more input than intended (the bugged part) and process the excess input. Since LP wasn't expecting all that extra output, it doesn't remove it from machines (works as intended). Installing cleanup upgrade makes LP remove extra output, preventing pileup of items in machines (workaround part).

So, you mean that item will sometimes stuck in the output, right?

Well, under some conditions machines get more input than intended (the bugged part) and process the excess input. Since LP wasn't expecting all that extra output, it doesn't remove it from machines (works as intended). Installing cleanup upgrade makes LP remove extra output, preventing pileup of items in machines (workaround part).

What do you mean by "conditions"?

Not sure what to say - I mean exactly what it means? You can replace "under some conditions" with "sometimes" or "in some cases", I guess.

Not sure what to say - I mean exactly what it means? You can replace "under some conditions" with "sometimes" or "in some cases", I guess.

I mean when it happens (the conditions)...

That's a question I wish I knew answer for! Others have reported that it happens after stoppting/starting server (reopening game) and it indeed seems like it does not happen if you never exit game.

Ok...
About stopping/starting server, LP not cache recipe processing like AE2 (using their processor) which cause items stuck at machine.

As far as I know, and this is from my experience way back in 1.4.7 MC versions of LP, LP does not "store/save" already-made requests when you reload the LP network either from reloading the chunk or relogging into the game.

I presume that is what the crafting cleanup upgrade is for - in the cases when you unexpectedly unload the LP network when an active request was being completed. Another workaround to prevent all these unprocessed items to clog up the system is to have an active supply of said items as well as using the cleanup upgrade as a preventative measure.